Background: Innovations and advancements with implant-based breast reconstruction, such as the use of ADMs, fat grafting, NSMs, and better implants, have enabled surgeons to now place breast implants in the pre-pectoral space rather than under the pectoralis major muscle. Breast implant replacement surgery in post-mastectomy patients, with pocket conversion from retro-pectoral to pre-pectoral, is becoming increasingly common, in order to solve the drawbacks of retro-pectoral implant positioning (animation deformity, chronic pain, and poor implant positioning). Materials and Methods: A multicentric retrospective study was conducted, considering all patients previously submitted to implant-based post-mastectomy breast reconstruction who underwent a breast implant replacement with pocket conversion procedure at the University Hospital of Udine—Plastic and Reconstructive Surgery Department—and “Centro di Riferimento Oncologico” (C.R.O.) of Aviano, from January 2020 to September 2021. Patients were candidates for a breast implant replacement with pocket conversion procedure if they met the following inclusion criteria: they underwent a previous implant-based post-mastectomy breast reconstruction and developed animation deformity, chronic pain, severe capsular contracture, or implant malposition. Patient data included age, body mass index (BMI), comorbidities, smoking status, pre- or post-mastectomy radiotherapy (RT), tumour classification, type of mastectomy, previous or ancillary procedures (lipofilling), type and volume of implant used, type of ADM, and post-operative complications (breast infection, implant exposure and malposition, haematoma, or seroma). Results: A total of 31 breasts (30 patients) were included in this analysis. Just three months after surgery, we recorded 100% resolution of the problems for which pocket conversion was indicated, which was confirmed at 6, 9, and 12 months post-operative. We also developed an algorithm describing the correct steps for successful breast-implant pocket conversion. Conclusion: Our results, although only early experience, are very encouraging. We realized that, besides gentle surgical handling, one of the most important factors in proper pocket conversion selection is an accurate pre-operative and intra-operative clinical evaluation of the tissue thickness in all breast quadrants.

Preoperative breast volume estimation is very important for the success of the breast surgery. In this study four different breast volume determination methods were compared. The end-point of this prospective study was to evaluate the concordance between different modalities of breast volume assessment (MRI, BREAST-V, mastectomy specimen weight, conversion from weight to volume of mastectomy specimen) and the breast prosthetic volume implanted. The study enrolled 64 patients between 2017 and 2019, who had all been treated by the same surgeons for monolateral nipple–areola complex-sparing mastectomy and implant breast reconstruction. Only patients who had a breast reconstruction classified as “excellent” from an objective (BCCT.core software) and subjective (questionnaire) point of view at the 6-month interval after the operation were included in the study. Data analysis highlighted a strong correlation between the volumes of the chosen prostheses and the weights of mastectomy converted into volume, especially for patients with grades B and C parenchymal density. The values of the agreement between the volumes of the chosen prostheses and the assessments from MRI and BREAST -V proved to be lower than expected from the literature. None of the four studied methods presented any strong correlation with the initial breast width. Our results suggest that conversion from weight to volume of mastectomy specimen should be used to assist in determining the volume of the breast implant to be implanted. This method would help the reconstructive surgeon guide the choice of the most appropriate implant preoperatively.